- 作者：
- Ilija Tovilo
ITPullToRefreshScrollView是NSScrollView的子类，允许通过下拉进行类似于iOS 7风格的刷新。ITPullToRefreshScrollView是为Play by Play应用程序创建的，由David Keegan提供资金。
感谢
- Sasmito Adibowo，很多代码基于RefreshableScrollView。
- Abhi Beckert提供的DuxScrollViewAnimation类。
- NachoSoto提供的NSBKeyframeAnimation类。
使用方法
将文件包含在项目中
ITPullToRefreshScrollView有两个子模块。您需要复制以下文件：
位于/ITPullToRefreshScrollView/Classes/下的文件：
ITPullToRefreshScrollView.hITPullToRefreshScrollView.mITPullToRefreshClipView.hITPullToRefreshClipView.mITPullToRefreshEdgeView.hITPullToRefreshEdgeView.mDuxScrollViewAnimation.hDuxScrollViewAnimation.m
位于/Modules/ITProgressIndicator/ITProgressIndicator/Classes/下的文件：
ITProgressIndicator.hITProgressIndicator.mNSBezierPath+Geometry.hNSBezierPath+Geometry.m
位于/Modules/NSBKeyframeAnimation/NSBKeyframeAnimation/Classes/NSBKeyframeAnimation/下的文件：
NSBKeyframeAnimation.hNSBKeyframeAnimation.mNSBKeyframeAnimationFunctions.hNSBKeyframeAnimationFunctions.c
请确保将它们复制到项目中，并将其添加到目标。
在项目中使用
请确保查看示例项目。
在Interface Builder中设置滚动视图的custom class为ITPullToRefreshScrollView。接下来您需要将一个IBOutlet连接到滚动视图。
@property (assign) IBOutlet ITPullToRefreshScrollView *scrollView;然后您可以在代码中配置，哪个滚动视图的边缘可以进行刷新。
// Make top & bottom refreshable
self.scrollView.refreshableEdges = ITPullToRefreshEdgeTop | ITPullToRefreshEdgeBottom;要接收来自滚动视图的通知，您需要创建一个代理。为此，您的代理类必须实现ITPullToRefreshScrollViewDelegate协议。然后您可以实现以下方法。
/**
* This method get's invoked when the scroll view started refreshing
*
* @param scrollView - The scroll view that started refreshing
* @param edge - The edge that started refreshing
*/
- (void)pullToRefreshView:(ITPullToRefreshScrollView *)scrollView
didStartRefreshingEdge:(ITPullToRefreshEdge)edge {
// Do stuff that takes very long
// Don't forget to call this line!
[scrollView stopRefreshingEdge:edge];
}
/**
* This method get's invoked when the scroll view stopped refreshing
*
* @param scrollView - The scroll view that stopped refreshing
* @param edge - The edge that stopped refreshing
*/
- (void)pullToRefreshView:(ITPullToRefreshScrollView *)scrollView
didStopRefreshingEdge:(ITPullToRefreshEdge)edge {
// Do UI stuff
}最后，您必须设置滚动视图的代理以接收通知。
self.scrollView.delegate = self;自定义
要创建自定义ITPullToRefreshEdgeView子类，覆写以下方法
// --------------------------
// ------------------- Events
// --------------------------
/**
* This method is called when the edge is triggered
*
* @param scrollView - The sender scroll view
*/
- (void)pullToRefreshScrollViewDidTriggerRefresh:(ITPullToRefreshScrollView *)scrollView;
/**
* This method is called when the edge is untriggered
*
* @param scrollView - The sender scroll view
*/
- (void)pullToRefreshScrollViewDidUntriggerRefresh:(ITPullToRefreshScrollView *)scrollView;
/**
* This method is called when the edge starts refreshing
*
* @param scrollView - The sender scroll view
*/
- (void)pullToRefreshScrollViewDidStartRefreshing:(ITPullToRefreshScrollView *)scrollView;
/**
* This method is called when the edge stops refreshing
*
* @param scrollView - The sender scroll view
*/
- (void)pullToRefreshScrollViewDidStopRefreshing:(ITPullToRefreshScrollView *)scrollView;
/**
* This method is called when part of the edge view becomes visible
*
* @param scrollView - The sender scroll view
* @param progress - The amount of the edge view that is visible (from 0.0 to 1.0)
*/
- (void)pullToRefreshScrollView:(ITPullToRefreshScrollView *)scrollView didScrollWithProgress:(CGFloat)progress;
// --------------------------
// ------------ Customisation
// --------------------------
/**
* Override this to remove the progress indicator and create other components
*/
- (void)installComponents;
/**
* The height of the edge view.
* Override this method to achieve a custom edge view height.
*
* @return The height of the edge view
*/
- (CGFloat)edgeViewHeight;
/**
* Override this method to draw a custom background.
* You can also just override `drawRect:` and to all the drawing on your own.
*
* @param The rect which should be drawn on
*/
- (void)drawBackgroundInRect:(NSRect)dirtyRect;